Keisuke Shigenaga
Mastering the machine through strategic insight.

Strategic technical consultant deployed to major enterprise clients across finance and public sectors.

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An unified platform for managing administrative tasks like address changes online. It allows users to update info across banks, insurance, and utilities simultaneously, ensuring efficiency and accuracy. As a full-stack engineer supporting 30+ banks and 10,000 users, I managed tech migrations, streamlined fault investigations, and achieved seamless team knowledge sharing.

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Evaluated the viability of code-gen platforms like OutSystems and .NET. Identified architectural risks by using decompilation for reverse engineering. Concluded that while useful for internal tools, they pose scalability risks for core systems, prioritizing long-term stability over short-term velocity.

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Spearheaded a legacy system migration by adopting Vue 3, achieving proficiency in one week and delivering core features under a tight timeline. Managed API integrations, audited Java backends to resolve critical defects, and prototyped UI components to ensure high velocity and system stability.

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Orchestrated a CakePHP 2 to 4 migration for a custom CMS, ensuring parity by auditing undocumented legacy code. Leveraged Java patterns to master the ORM, developed utility functions for version gaps, and authored the team playbook to standardize the roadmap and ensure long-term stability.

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Led the shift from custom builds to a scalable enterprise portal by developing reusable Java components. Prioritized maintainability via SOLID principles and JUnit testing, while ensuring clarity through PlantUML. My full-stack expertise optimized deployment and team-wide productivity.

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Developed a high-performance portfolio site using React and TypeScript to demonstrate professional engineering proficiency. Engineered a responsive UI with decoupled card-and-dialog components for seamless cross-platform consistency while showcasing complex project details and AI integrations.

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A NestJS (TypeScript) API that drafts corporate communications and PR-style copy from pasted text or public article URLs. It calls the OpenAI API and returns structured JSON—summary, email subject, email body, and bullet key points. Article URLs are fetched via the Jina Reader HTTP API instead of scraping raw HTML; a separate pr-agent module is experimental scaffolding for GitHub pull-request workflows.

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A web-based implementation of the strategic board game Slipe on a 5x5 grid. The project focuses on non-trivial game logic such as directional slide movement, turn-aware validation, and win-condition checks, while keeping UI feedback intuitive through real-time move hints and contextual status messaging.

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